The present invention relates generally to medium trays for use in recording media library apparatuses of the type which transfers a designated recording medium by transferring a tray supporting thereon the recording medium, and more particularly to an improved technique for achieving a smooth transfer of the medium tray through simplified positioning control.
Conventionally-known recording media library apparatuses (hereinafter also referred to as xe2x80x9clibrary apparatusesxe2x80x9d) are designed in such a way that a recording medium, such as an optical disk, contained in a predetermined case or cartridge is transported automatically by a computer-controlled carrying holder unit between a storage unit and a medium drive unit and the thus-transported medium is driven via the drive unit for data read/write. Namely, such library apparatuses generally comprise the carrying holder unit automatically-controlled for retaining and transporting a designated recording medium, usually in horizontal and vertical directions, the storage unit for storing a multiplicity of the recording media in respective storage cells (or on respective storage racks), and the medium drive unit that reads and/or writes data on the recording medium. The carrying holder unit includes a handling (or feed-transfer) mechanism which function to pass a recording medium between a selected one of the storage cells and the drive unit.
More and more DVDs (Digital Versatile Disks) have been used as high-density digital recording media in recent years. However, so far, there has been proposed no library apparatus capable of efficiently handling the DVD recording media.
In some of the library apparatuses handling disk-shaped recording media, such as DVDs (Digital Versatile Disks) or CDs (Compact Disks), or other-type recording media which can not be directly retained by the carrying holder unit for the transfer purpose, each of the media is supported on a separate mount or tray (i.e., one tray per recording medium) and handled or transferred along with the tray. One typical example of the conventionally-known tray is shown in FIG. 9. This tray 100 is square or rectangular in shape and has a plurality of engaging recesses (commonly known as xe2x80x9cpick notchesxe2x80x9d in the art) 102 formed near its corners. In FIG. 9, a locking claw or picker 40 of a carrying holder unit 20 is shown as being in engagement with a particular one of the engaging recesses 102a. The locking claw 40 thus engaging the recess 102a is moved in the horizontal direction (denoted by arrow X) to transfer the tray 100 to or from the holder unit 20.
The tray 100 is sometimes transferred with some vertical (upward or downward) inclination relative to the horizontal transfer direction X. If such an inclination of the tray 100 is greater than a tolerable degree, the leading end 101 (as viewed in the direction where the tray 100 is being transferred) of the tray 100 would collide against a front wall portion of the holder unit 20 defining its medium entry/exit opening (hereinafter called a xe2x80x9cmedium entry/exitxe2x80x9d). For example, when the tray 100 is pulled out of one of a plurality of storage cells of the storage unit (not shown) into the carrying holder unit 20, the leading end 101 may collide against the entry/exit of the holder unit 20, and when the tray 100 is sent out from the holder unit 20 into the storage cell, the other end (leading end at this time) 101 may collide against a front wall portion of the storage cell defining its entry/exit opening (hereinafter called a xe2x80x9cmedium entry/exitxe2x80x9d). Because of the square or rectangular shape, the leading end of the conventionally-known tray 100 normally comes into a collision with the entry/exit while maintaining parallel relationship to the entry/exit.
However, with the recording media library apparatuses using such a conventional square- or rectangle-shaped tray for transfer of a recording medium, it was usually necessary to suspend the intended transfer of the tray each time the tray collided with the entry/exit of the storage cell or holder unit, which substantially lowered the efficiency in the necessary transfer of the recording media. Therefore, various attempts and suggestions have been made to avoid such an unwanted collision. One of the approaches proposed so far is to just cause the two engaging recesses, formed in opposite side edges adjacent to the leading end, to be engaged simultaneously so that the tray can be transferred with the tray""s leading end portion kept in the horizontal plane to thereby prevent a vertical inclination of the entire tray. However, such an approach would require a complicated tray transfer mechanism, thus resulting in an increased size and manufacturing cost of the library apparatus.
It is therefore an object of the present invention to provide a recording media library apparatus which permits a continued smooth transfer of a medium tray even when the tray, due to its inclination, collides at its leading end against a medium entry/exit of a designated destination component of the apparatus.
In order to accomplish the above-mentioned object, the present invention provides a mount for a recording medium, which is transferred at least in a predetermined horizontal transfer direction to be passed to a designated destination component in such a way that the recording medium supported on the mount is received, along with the mount, in place within the destination component, and which is characterized in that the mount has one end surface oriented in the horizontal transfer direction and the one end surface is slanted with respect to a direction normal to the horizontal transfer direction.
The term xe2x80x9cdestination componentxe2x80x9d is used herein to generically refer to every such component which is arranged to receive a recording medium transferred on the mount, and examples of the destination component include storage cells (or storage racks), medium carrying holder unit and medium drive unit in a recording media library apparatus.
According to another aspect of the present invention, there is provided a recording media library apparatus which comprises: a mount for supporting thereon a recording medium, the mount having at least one end surface oriented in a predetermined horizontal transfer direction thereof, the one end surface being slanted with respect to a direction normal to the horizontal transfer direction; a storage section that stores therein a plurality of the mounts each supporting the recording medium; a medium drive unit that reads and/or write data on the recording medium; and a transportation mechanism that carries the mount between the storage section and the medium drive unit and performs a predetermined handling operation to pass, in the horizontal transfer direction, the mount to or from the storage section or the medium drive unit. In this library apparatus, even when the mount being transferred comes into collision with the front wall of the storage section, medium drive unit or carrying holder unit which is designated as the destination component, the mount is allowed to gradually slide along the wall surface into a predetermined place within the destination component, so that the recording medium supported on the mount can be smoothly passed into the destination component.
With the conventionally-known mounts, a large area of the one end surface, oriented in the tray-transfer direction, would simultaneously contact (or collide against) a front wall surface of the entry/exit of the designated destination component. The provision of the slanted end surface can effectively reduce the area of the simultaneous contact with the front wall surface of the designated destination component. The reduced area of the contact between the end surface of the mount and the destination component achieves a significantly reduced frictional resistance therebetween. The reduced frictional resistance will achieve a smooth sliding movement of the medium tray into the destination component such as the storage cell, holder unit or drive unit.
Because the mount can be smoothly transferred and inserted into the designated destination component even when it initially comes into a collision with the front wall surface of the medium entry/exit of the destination component in the above-mentioned manner, the present invention eliminates a need for accurately positioning the carrying holder unit relative to the medium entry/exit, which greatly simplifies the necessary positioning control. With the thus-simplified positioning control, the mechanism for carrying the mount can also be significantly simplified, with the result that the cost and size of the recording media library apparatus can be reduced greatly as compared to the known library apparatuses.